There is no single Australian mortgage calculator used by every bank. Each lender builds its own credit model within regulatory expectations. The result is that one lender may be conservative with overtime, another with rental income, another with self-employed add-backs, and another with the way it assesses existing investment debt.
- Income shading varies
- Existing debt assessment varies
- Rental income treatment varies
- Self-employed add-backs vary
- Policy fit matters as much as the headline capacity
Income is not treated uniformly
One lender may use a long history of overtime or bonus income while another uses a lower percentage or excludes it. Rental income is commonly shaded and different lenders recognise different portions of gross rent.
Foreign income, commissions, allowances, probation and recent job changes can all produce lender-specific outcomes.
Debt assessment methodology matters
An existing loan can be assessed using its actual remaining term, a stressed rate, a principal-and-interest repayment even if it is interest-only, or another prescribed methodology. Small differences across several debts compound quickly.
Credit cards and buy-now-pay-later facilities can also be treated differently.
The right lender is not simply the one with the biggest number
Maximum borrowing power is useful only if the lender’s rate, features, valuation policy, cash-out rules and future strategy also fit. Chasing capacity without considering structure can create problems later.
The aim is to find a lender that can support the transaction responsibly while preserving as much future flexibility as practical.
Frequently asked questions
Can capacity really differ by more than $100,000?
Yes, particularly for investors, self-employed borrowers, foreign-income earners and borrowers with complex existing debts.
Should I apply to several banks to compare?
A broker can compare servicing before lodging applications, which can reduce unnecessary credit enquiries.
Is the highest-capacity lender always best?
No. Product cost, structure, valuation and future policy needs should also be considered.